紫花苜蓿和印度芥菜对土壤中铅的吸收特性研究

目的]研究紫花苜蓿和印度芥菜对土壤中铅的吸收特性。方法]采用盆栽试验,土壤中铅离子浓度为0、100、500、1 000、2 000、3 000 mg/kg干土,测定紫花苜蓿、印度芥菜地上部和根部的铅含量,计算铅的迁移总量、根系耐性指数、富集系数。结果]随着铅离子浓度的增加,2种植物地上部对铅的迁移总量上升,且印度芥菜对铅的迁移总量较大。2种植物的根系耐性指数在3 000 mg/kg处理下小于1,其他处理下大于1。2种植物的根部铅富集系数在各处理下均大于地上部,且印度芥菜的铅富集能力大于紫花苜蓿。2种植物根部和地上部的铅含量均与土壤中铅添加量呈显著的线性相关。结论]紫花苜蓿和印度芥菜对土壤中的铅均具有较强的富集作用。

Study on Absorption Characteristics of Medicago sativa and Brassica juncea on Pb in Soil

Objective] The aim was to study the Absorption characteristics of Medicago sativa and Brassica juncea on Pb in soil.Method] In the pot experiment,the lead ion concn.in the dry soils was set as 0,100,500,1 000,2 000 and 3 000 mg/kg,the content of Pb in aerial parts and root of M.sativa and B.juncea were detected and the total migration amount of Pb,root tolerance index and enrichment coefficient were calculated.Result] The total migration amount of the 2 kinds of plants in aerial parts on Pb was increased with the increase of lead ion concn.and that of B.juncea on Pb was bigger.The root tolerance index of the 2 kinds of plants in the treatment of 3 000 mg/kg lead ion was less than 1 and that in the other treatments were above 1.The enrichment coefficient of the root of the 2 kinds of plants in each treatment was bigger than that in aerial parts and the enrichment ability of B.juncea was bigger than that of M.sativa.The content of Pb in root and aerial parts of the 2 kinds of plants all had significant linear correlation with the addition of Pb in soil.Conclusion] M.sativa and B.juncea all had stronger enrichment on Pb in soil.